Authentication methods have traditionally included usage of username and password along with other, sometimes optional, information about the user or the machine at the time of requesting access to computer systems or servers. In many cases, the servers are capable of request other information in order to grant admission to the entering machine or user. Of which, it includes checking the IP address or domain of the client while logging in. For added security, sometimes an expiration time has been added to the login sessions to disable the session in case a longer than expected time is needed by the client to login. In order to ensure automated and/or repeated login attempts, which can translate to problems for the security of the system, are prevented, in many cases the client is asked to identify a convoluted set of letters, numbers or signs shown in a picture believed to be easily recognizable only by human brain.
In other forms of added reliability and security for an authentication system, biometric fingerprint recognition has been used. Fingerprint (FP) recognition refers to methods used for determining the existence of a match between two human fingerprints. In these methods, several features of the FP are compared including the patterns and minutia features. The patterns include whorl, loop, and arch. Furthermore, FPs have unique minute features which belong to categories of ridge endings, bifurcations, and short ridges or dots. For the purposes of computer security or other similar applications, fingerprints are captured by sensors to create a digital image of the pattern. A biometric template is created by digitally processing the digital image to make available a collection of extracted features. This collection is used for matching. Common FP sensors include optical, ultrasonic, and capacitance sensors. The optical sensor, for instance, is essentially a specialized digital camera under a layer of transparent material. Finger is placed on the transparent material, surface of the finger is illuminated, and pictures are taken to be processed in the next stage.
A combination of the two authentication methods, namely the username/password method and the fingerprint recognition method would greatly increase the security of the system. Systems have been developed in which the two mentioned processes are performed serially. That is, for added security, one enters his/her username and password and then is prompted to put finger on a touch pad. This method is inconvenient, usually takes twice as much time as a regular authentication process and unavoidably reveals that a FP process is being performed.
Some of the known applications include a biometric reader, which the screen can be used for logging back, in case the user is locked out or has forgotten user name or password. In addition, timing defaults for enabling the screen to lock can be set. An additional solution is required for the cases that fall between the timing and forgetfulness periods for future tablet PCs.